Machine tool support assembly



Nov. 20, 1951 M. I. MATHEWSON MACHINE TOOL SUPPORT ASSEMBLY 2 SHEETSr-Sl'lEET 1 Filed Dec. 30, 1948 lll ll Nov. 20, 1951 V M. L'MATHEWSON 2,575,823

MACHINE TOOL SUPPORT ASSEMBLY Filed Dec. so, 1948 2 SHEETS-SHEET 2 Patented Nov. 20, 1951 UNITED STATES PATENT OFFICE,

2,575,823 MACHINE TOOL SUPPORT ASSEMBLY Maxwell I. Mathewson, Providence, R. I., assignor to Brown and Sharpe Manufacturing Company, Providence, R. 'I., a corporation of Rhode Island 6 Claims. l The present invention relates to improvements in machinetools, and more particularly to an improved grinding wheel spindle support assembly for use in a cylindrical grinding machine.

The inventionis herein disclosed as embodied Application December 30, 1948, Serial No. 68,319

in a universal grinding machine of which the principal parts include a base, a longitudinally movable work table, and a grinding wheel spindle support which is mounted for both transverse movement with respect to the work support and for rotational adjustment about vertical axes. The grinding wheel spindle supporting assembly includes specifically a grinding wheel spindle support on which are mounted a rotary grinding wheel spindle and its driving motor, a wheel slide on which the wheel support is rotatably adjustable, and a swivel support for the wheel slide carried on the base. Machines of this general description as heretofore constructed have been provided with adjusting means to permit a limited forward and back adjustment of the wheel support on the wheel slide, which has been found to be of advantage to increase the effective range of forward and back movement of the grinding wheel without so far extending the "movement of the wheel slide as to unbalance the grinding wheel support assembly.

It is a principal object of the present invention to provide in a machine of this general description an improved means for effecting an adjustment. in the position of the wheel support on the wheel slide, which adjustment may be made with a minimum of labor, which substantially increases the range of possible adjustment of position of the wheelsupport, and which further assures that the wheel support assembly .will provide a support of maximum strength for the wheel slide will have the effect of adjusting. the position of the grinding wheel with relation to the wheel slide between extreme forward and, rearward positions, and additionally of adjusting;

the position of the grinding wheel with relation to the wheel slide between two extreme positions laterally in which, the grinding wheel V spindle is so disposed asto increase. the effective range of movement of the longitudinally moving work support either in one or the other direction.

Further in accordance with the invention, the swivel support on the wheel slide platen is constructed and arranged to include a single clamping bolt which extends downwardly through the center of the wheel support swivel and is adapted to be screw threaded into any one of a plurality of internally screw-threaded sockets in the wheel slide so that the wheel support and platen on which the wheel support is mounted are rigidly and directly secured to the wheel slide.

With the above-noted and other objects in view as may hereinafter appear, the several features of the invention consist also of the devices, combinations and arrangement of parts hereinafter described and claimed which, together with the advantages to be obtained thereby, will be readily understood from the following description taken in connection with the-accompanying drawings, in which i Fig. 1 is a view in side elevation of a universal cylindrical grinding machine 'with portions broken away or sectioned to illustrate particularly the assembled parts of the grinding wheel supporting assembly, only so much of i the machine having been shown as is believed. necessary to illustrate the connection of the invention therewith;

Fig. 2 is a sectional plan view taken on the line 22 of Fig. 1 to illustrate particularly the construction and arrangement of the wheel slide platen of the machine; and

Fig. 3 is a detail sectional view taken on a line 33 of Fig; 2, illustrating the detent employed for determining the angular position of the wheel slide platen with relation to the wheel slide. a

The universal cylindrical grinding machine illustrated in the drawings as embodying in a preferred form the several features of the invention comprises a base, generally indicated at 10, a longitudinally .movable work support I2 on which are mounted a footstock and, headstock (not shown) for rotatably supporting a work piece. The machine is shown as provided with the usual cylindrical grinding wheel I6 and grinding wheel spindle l3 supported to ,turn on a horizontal axis in a grinding wheel support 20 for the performance of external grinding operations. The illustrated machine is also provided with an internal grinding fixture which is shown in its operative position and comprises 'an internal grinding bracket 22 on which is mounted an internal grinding wheel spindle 24. i v Power to drive the grindingwheel spindle above described is provided by an electric motor 26 rigidly secured on a platform 28 provided on a rearward extension of the wheel support 20. The spindle I8 is directly driven from the armature shaft of'the motor by means of a belt 38 which passes around a pulley 32 on the spindle I8 and a pulley 34 on the armature shaft of the motor. A direct drive is provided to the internal grinding attachment from the motor 26, when desired, for the performance of internal grinding operations by means of a belt, indicated in dot and dash lines at 36, which passes over a pulley 38 on the internal grinding wheel spindle 24 and over a large pulley 40 on the armature shaft of the motor.

The wheel spindle supporting assembly, in accordance with the usual construction of machines of the type disclosed, includes a wheel slide 42 on which the wheel support is normally mounted for rotational adjustment, a wheel slide base I 44 having ways on which the wheel slide is supported for sliding movement toward and away from the worktable, and a bed 46 providing a swivel support on which the Wheel slide base is rotatably adjustable about a vertical axis. indicated in Fig. 1 of the drawings, power means are provided for moving the wheel slide forward and back on its base, including a vertically disposed drive shaft 48 which extends up through the axis of the swivel support for the wheel slide base and is connected by beveled gears 50, 52 with a wheel slide feed screw 54 rotatably supported in the wheel slide bed and arranged for engagement with a cooperating nut carried by the wheel slide. It will be understood that the con- 'swivel axis of adjustment of the wheel slide 42 with relation to the wheel slide platen 58. The under side of the wheel support is formed with a fiat circular bearing surface which engages a correspondingly formed circular bearing surface 60 formed on the upper face of the wheel slide platen 58. A cylindrical bushing 62 having the lower portion thereof of reduced diameter, fitted into a bearing'hole in the wheel slide platen 58 and having the upper enlarged portion thereof engaging with a cylindrical bearing 66, provides a swivel about which the wheel support is angularly adjustable. The bottom face of the wheel slide platen is shaped to provide a fiat circular disk-like bearing surface 68 which is of substantially larger diameter and is eccentric to the bearing surface 60 forming the upper face of the wheel stand platen. The bottom bearing surface 68 of the wheel slide platen engages with a cooperating circular bearing surface forming the upper face of the wheel slide 42. A pin in having an enlarged upper end thereof fitted into a cylindrical bearing surface ,in the platen and having the reduced lower portion thereof fitted into a cylindrical bearing surface formed in the wheel slide, provides a swivel connection about which the wheel slide platen is freely rotatable on the wheel slide 42. The platen 58 is fixedly supported in each of its four adjusted positions by means of jatapered spring -pressed plunger 64 which is 4 mounted on the wheel slide 42 to extend upwardly into any one of four tapered sockets 1| formed in the bottom bearing surface of the wheel slide platen 58.

This arrangement of the wheel slide and interposed wheel slide platen having swivel connections with respective-wheel slide and wheel support offset from one another, provides a ready means for adjustment of the position of the wheel support both forward and back, and laterally, which has been found to have substantial advantages as compared with the slide adjustment connections between the wheel stand and a wheel slide provided by the prior art. One very substantial advantage noted is concerned with the problem of maintaining in a clean condition the operating surfaces of the machine. The circular movements here provided for permit maintaining the bearing surfaces continuously covered so that no inaccuracies will result from the-inadvertent inclusion of grit or other obstructions upon the bearing surfaces.

Further inorder to ensure a rigid unyielding construction of the grinding wheel assembly when in use, a simple and at the same time efficient clamping device is employed which is well adapted to rigidly clamp the wheel support inits adjusted position on the wheel slide. To this end there are provided four threaded sockets 12 which are disposed at equal distances from one another in the circumference of a circle described about the swivel axis of rotation of the platen provided by the swiveling pin 10. A vertically disposed clamping bolt 14 which extends down through a central bore 16 in the wheel support .20 and through the hollow bushing 62 which provides swivel support for the wheel support on the platen, is adapted to be threaded into any one of the sockets 12. 'The tightening of the bolt 74 into any one of the four sockets, depending upon the adjusted position of the platen; will have the effect of securely fasteningthe wheel support and platen rigidly to the wheel slide. A compression spring 18 coiled about the shank of the bolt 14' between a shoulder 80 formed in the wall of the central bore 16 and a shoulder 82' on the bolt acts to urge the bolt upwardly when it is unthreaded from its socket 12 so thatthe lower end of the bolt may be fully withdrawn from the socket during adjustment'of the platen and bolt from one position of adjustment to another.

The invention having been described, what is claimed is:

1'. In a grindin machine having a rotary grinding wheel spindle, a grinding wheel supporting assembly which comprises a grinding wheel support, a wheel slide on which the grinding wheel support is carried, and a platen interposed between the grinding wheel support and the wheel slide having swivel connections eccentric to one another including cooperating bear- 7 comprises a rotary tool spindle-support; a platen and a swivel on which the rotary tool spindle support is rotatably adjustable about a vertical axis on the platen, a tool slide on which the platen is rotatably adjustable about an axis eccentric to said swivel axis, clamping means comprising a screw-threaded bolt supported on the rotary tool spindle support along said swivel axis, and a cooperating threaded element in the tool slide to receive said bolt for clamping together the tool support, platen and tool slide.

3. In a machine tool having a rotary tool spindle, a rotary tool supporting assembly which comprises a rotary tool spindle support, a platen providing a swivel support on which the rotary tool spindle support is adjustable about a vertical axis, a tool slide on which the platen is 1'0- tatably adjustable about an axis eccentric to said swivel axis, and clamping means comprising a clamping element supported on the rotary tool spindle support alon said swivel axis, and a plurality of cooperating clamping elements disposed on the tool slide about the axis of rotation of the platen on the tool slide adapted to cooperate selectively with said first-named clamping element for rigidly securing the rotary tool spindle support and platen to the tool slide.

4. In a grinding machine having a rotary grinding wheel spindle, a grinding Wheel supporting assembly which comprises a grinding wheel spindle support, a platen, a swivel, and cooperating bearing surfaces on the platen and wheel support on which the grinding wheel support, platen, and wheel slide rigidly together,

and a positioning device comprising a detent member and a plurality of cooperating sockets on the wheel slide and platen for latching the platen in any one of a plurality of adjusted positions on the wheel slide.

5. In a grinding machine having a rotary grinding wheel spindle, a grinding wheel supporting assembly which comprises a grinding wheel spindle support, a platen, a swivel, and

cooperating bearing surfaces on the platen and wheel support on which the wheel support is rotatably adjustable about a vertical axis, a wheel slide, cooperating bearing surfaces on the wheel slide and on the platen on which the platen is rotatably adjustable about a vertical axis eccentric to the swivel axis for adjustment in the position of the wheel support, including the swivel axis thereof, with relation to the tool slide, clamping means comprising a clamping element on the wheel slide disposed along said swivel axis, and cooperating clamping elements disposed on the wheel slide about said axis of rotation of the platen for selective cooperation with said first-named clamping element for rigidly securing together said wheel support, platen, and wheel slide.

6. In a grinding machine having a rotary grinding wheel spindle. a grinding wheel supporting assembly which comprises a grinding wheel support, a wheel slide, a turntable on which the wheel slide is carried, and a platen interposed between the grinding wheel support and the wheel slide having swivel connections eccentric to one another including cooperating bearin surfaces on the platen and on each of the grinding wheel support and the wheel slide whereby rotational adjustment of the platen is effective to adjust the position of the grinding wheel support including the swivel connection therewith both longitudinally and transversely with relation to the wheel slide, and a clamping device connected between the grinding wheel support and the wheel slide for clamping the grinding wheel support, platen, and. wheel slide rigidly together.

MAXYVELL I. MATHEVVSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

